/*
 * winsftp.c: the Windows-specific parts of PSFTP and PSCP.
 */

#include <winsock2.h> /* need to put this first, for winelib builds */
#include <assert.h>

#define NEED_DECLARATION_OF_SELECT

#include "putty.h"
#include "psftp.h"
#include "ssh.h"
#include "int64.h"
#include "winsecur.h"

char *get_ttymode(void *frontend, const char *mode)
{
  return NULL;
}

int get_userpass_input(prompts_t *p, const unsigned char *in, int inlen)
{
  int ret;
  ret = cmdline_get_passwd_input(p, in, inlen);
  if (ret == -1)
    ret = console_get_userpass_input(p, in, inlen);
  return ret;
}

void platform_get_x11_auth(struct X11Display *display, Conf *conf)
{
  /* Do nothing, therefore no auth. */
}
const int platform_uses_x11_unix_by_default = TRUE;

/* ----------------------------------------------------------------------
 * File access abstraction.
 */

/*
 * Set local current directory. Returns NULL on success, or else an
 * error message which must be freed after printing.
 */
char *psftp_lcd(char *dir)
{
  char *ret = NULL;

  if (!SetCurrentDirectory(dir)) {
    LPVOID message;
    int i;
    FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
                      FORMAT_MESSAGE_IGNORE_INSERTS,
                  NULL,
                  GetLastError(),
                  MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                  (LPTSTR)&message,
                  0,
                  NULL);
    i = strcspn((char *)message, "\n");
    ret = dupprintf("%.*s", i, (LPCTSTR)message);
    LocalFree(message);
  }

  return ret;
}

/*
 * Get local current directory. Returns a string which must be
 * freed.
 */
char *psftp_getcwd(void)
{
  char *ret = snewn(256, char);
  int len = GetCurrentDirectory(256, ret);
  if (len > 256)
    ret = sresize(ret, len, char);
  GetCurrentDirectory(len, ret);
  return ret;
}

#define TIME_POSIX_TO_WIN(t, ft)                                               \
  do {                                                                         \
    ULARGE_INTEGER uli;                                                        \
    uli.QuadPart = ((ULONGLONG)(t) + 11644473600ull) * 10000000ull;            \
    (ft).dwLowDateTime = uli.LowPart;                                          \
    (ft).dwHighDateTime = uli.HighPart;                                        \
  } while (0)
#define TIME_WIN_TO_POSIX(ft, t)                                               \
  do {                                                                         \
    ULARGE_INTEGER uli;                                                        \
    uli.LowPart = (ft).dwLowDateTime;                                          \
    uli.HighPart = (ft).dwHighDateTime;                                        \
    uli.QuadPart = uli.QuadPart / 10000000ull - 11644473600ull;                \
    (t) = (unsigned long)uli.QuadPart;                                         \
  } while (0)

struct RFile {
  HANDLE h;
};

RFile *open_existing_file(const char *name,
                          uint64 *size,
                          unsigned long *mtime,
                          unsigned long *atime,
                          long *perms)
{
  HANDLE h;
  RFile *ret;

  h = CreateFile(
      name, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, 0);
  if (h == INVALID_HANDLE_VALUE)
    return NULL;

  ret = snew(RFile);
  ret->h = h;

  if (size) {
    DWORD lo, hi;
    lo = GetFileSize(h, &hi);
    size->lo = lo;
    size->hi = hi;
  }

  if (mtime || atime) {
    FILETIME actime, wrtime;
    GetFileTime(h, NULL, &actime, &wrtime);
    if (atime)
      TIME_WIN_TO_POSIX(actime, *atime);
    if (mtime)
      TIME_WIN_TO_POSIX(wrtime, *mtime);
  }

  if (perms)
    *perms = -1;

  return ret;
}

int read_from_file(RFile *f, void *buffer, int length)
{
  int ret;
  DWORD read;
  ret = ReadFile(f->h, buffer, length, &read, NULL);
  if (!ret)
    return -1; /* error */
  else
    return read;
}

void close_rfile(RFile *f)
{
  CloseHandle(f->h);
  sfree(f);
}

struct WFile {
  HANDLE h;
};

WFile *open_new_file(const char *name, long perms)
{
  HANDLE h;
  WFile *ret;

  h = CreateFile(
      name, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
  if (h == INVALID_HANDLE_VALUE)
    return NULL;

  ret = snew(WFile);
  ret->h = h;

  return ret;
}

WFile *open_existing_wfile(const char *name, uint64 *size)
{
  HANDLE h;
  WFile *ret;

  h = CreateFile(
      name, GENERIC_WRITE, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, 0);
  if (h == INVALID_HANDLE_VALUE)
    return NULL;

  ret = snew(WFile);
  ret->h = h;

  if (size) {
    DWORD lo, hi;
    lo = GetFileSize(h, &hi);
    size->lo = lo;
    size->hi = hi;
  }

  return ret;
}

int write_to_file(WFile *f, void *buffer, int length)
{
  int ret;
  DWORD written;
  ret = WriteFile(f->h, buffer, length, &written, NULL);
  if (!ret)
    return -1; /* error */
  else
    return written;
}

void set_file_times(WFile *f, unsigned long mtime, unsigned long atime)
{
  FILETIME actime, wrtime;
  TIME_POSIX_TO_WIN(atime, actime);
  TIME_POSIX_TO_WIN(mtime, wrtime);
  SetFileTime(f->h, NULL, &actime, &wrtime);
}

void close_wfile(WFile *f)
{
  CloseHandle(f->h);
  sfree(f);
}

/* Seek offset bytes through file, from whence, where whence is
   FROM_START, FROM_CURRENT, or FROM_END */
int seek_file(WFile *f, uint64 offset, int whence)
{
  DWORD movemethod;

  switch (whence) {
  case FROM_START:
    movemethod = FILE_BEGIN;
    break;
  case FROM_CURRENT:
    movemethod = FILE_CURRENT;
    break;
  case FROM_END:
    movemethod = FILE_END;
    break;
  default:
    return -1;
  }

  {
    LONG lo = offset.lo, hi = offset.hi;
    SetFilePointer(f->h, lo, &hi, movemethod);
  }

  if (GetLastError() != NO_ERROR)
    return -1;
  else
    return 0;
}

uint64 get_file_posn(WFile *f)
{
  uint64 ret;
  LONG lo, hi = 0;

  lo = SetFilePointer(f->h, 0L, &hi, FILE_CURRENT);
  ret.lo = lo;
  ret.hi = hi;

  return ret;
}

int file_type(const char *name)
{
  DWORD attr;
  attr = GetFileAttributes(name);
  /* We know of no `weird' files under Windows. */
  if (attr == (DWORD)-1)
    return FILE_TYPE_NONEXISTENT;
  else if (attr & FILE_ATTRIBUTE_DIRECTORY)
    return FILE_TYPE_DIRECTORY;
  else
    return FILE_TYPE_FILE;
}

struct DirHandle {
  HANDLE h;
  char *name;
};

DirHandle *open_directory(const char *name)
{
  HANDLE h;
  WIN32_FIND_DATA fdat;
  char *findfile;
  DirHandle *ret;

  /* Enumerate files in dir `foo'. */
  findfile = dupcat(name, "/*", NULL);
  h = FindFirstFile(findfile, &fdat);
  if (h == INVALID_HANDLE_VALUE)
    return NULL;
  sfree(findfile);

  ret = snew(DirHandle);
  ret->h = h;
  ret->name = dupstr(fdat.cFileName);
  return ret;
}

char *read_filename(DirHandle *dir)
{
  do {

    if (!dir->name) {
      WIN32_FIND_DATA fdat;
      int ok = FindNextFile(dir->h, &fdat);
      if (!ok)
        return NULL;
      else
        dir->name = dupstr(fdat.cFileName);
    }

    assert(dir->name);
    if (dir->name[0] == '.' &&
        (dir->name[1] == '\0' ||
         (dir->name[1] == '.' && dir->name[2] == '\0'))) {
      sfree(dir->name);
      dir->name = NULL;
    }

  } while (!dir->name);

  if (dir->name) {
    char *ret = dir->name;
    dir->name = NULL;
    return ret;
  } else
    return NULL;
}

void close_directory(DirHandle *dir)
{
  FindClose(dir->h);
  if (dir->name)
    sfree(dir->name);
  sfree(dir);
}

int test_wildcard(const char *name, int cmdline)
{
  HANDLE fh;
  WIN32_FIND_DATA fdat;

  /* First see if the exact name exists. */
  if (GetFileAttributes(name) != (DWORD)-1)
    return WCTYPE_FILENAME;

  /* Otherwise see if a wildcard match finds anything. */
  fh = FindFirstFile(name, &fdat);
  if (fh == INVALID_HANDLE_VALUE)
    return WCTYPE_NONEXISTENT;

  FindClose(fh);
  return WCTYPE_WILDCARD;
}

struct WildcardMatcher {
  HANDLE h;
  char *name;
  char *srcpath;
};

char *stripslashes(const char *str, int local)
{
  char *p;

  /*
   * On Windows, \ / : are all path component separators.
   */

  if (local) {
    p = strchr(str, ':');
    if (p)
      str = p + 1;
  }

  p = strrchr(str, '/');
  if (p)
    str = p + 1;

  if (local) {
    p = strrchr(str, '\\');
    if (p)
      str = p + 1;
  }

  return (char *)str;
}

WildcardMatcher *begin_wildcard_matching(const char *name)
{
  HANDLE h;
  WIN32_FIND_DATA fdat;
  WildcardMatcher *ret;
  char *last;

  h = FindFirstFile(name, &fdat);
  if (h == INVALID_HANDLE_VALUE)
    return NULL;

  ret = snew(WildcardMatcher);
  ret->h = h;
  ret->srcpath = dupstr(name);
  last = stripslashes(ret->srcpath, 1);
  *last = '\0';
  if (fdat.cFileName[0] == '.' &&
      (fdat.cFileName[1] == '\0' ||
       (fdat.cFileName[1] == '.' && fdat.cFileName[2] == '\0')))
    ret->name = NULL;
  else
    ret->name = dupcat(ret->srcpath, fdat.cFileName, NULL);

  return ret;
}

char *wildcard_get_filename(WildcardMatcher *dir)
{
  while (!dir->name) {
    WIN32_FIND_DATA fdat;
    int ok = FindNextFile(dir->h, &fdat);

    if (!ok)
      return NULL;

    if (fdat.cFileName[0] == '.' &&
        (fdat.cFileName[1] == '\0' ||
         (fdat.cFileName[1] == '.' && fdat.cFileName[2] == '\0')))
      dir->name = NULL;
    else
      dir->name = dupcat(dir->srcpath, fdat.cFileName, NULL);
  }

  if (dir->name) {
    char *ret = dir->name;
    dir->name = NULL;
    return ret;
  } else
    return NULL;
}

void finish_wildcard_matching(WildcardMatcher *dir)
{
  FindClose(dir->h);
  if (dir->name)
    sfree(dir->name);
  sfree(dir->srcpath);
  sfree(dir);
}

int vet_filename(const char *name)
{
  if (strchr(name, '/') || strchr(name, '\\') || strchr(name, ':'))
    return FALSE;

  if (!name[strspn(name, ".")]) /* entirely composed of dots */
    return FALSE;

  return TRUE;
}

int create_directory(const char *name)
{
  return CreateDirectory(name, NULL) != 0;
}

char *dir_file_cat(const char *dir, const char *file)
{
  return dupcat(dir, "\\", file, NULL);
}

/* ----------------------------------------------------------------------
 * Platform-specific network handling.
 */

/*
 * Be told what socket we're supposed to be using.
 */
static SOCKET sftp_ssh_socket = INVALID_SOCKET;
static HANDLE netevent = INVALID_HANDLE_VALUE;
char *do_select(SOCKET skt, int startup)
{
  int events;
  if (startup)
    sftp_ssh_socket = skt;
  else
    sftp_ssh_socket = INVALID_SOCKET;

  if (p_WSAEventSelect) {
    if (startup) {
      events =
          (FD_CONNECT | FD_READ | FD_WRITE | FD_OOB | FD_CLOSE | FD_ACCEPT);
      netevent = CreateEvent(NULL, FALSE, FALSE, NULL);
    } else {
      events = 0;
    }
    if (p_WSAEventSelect(skt, netevent, events) == SOCKET_ERROR) {
      switch (p_WSAGetLastError()) {
      case WSAENETDOWN:
        return "Network is down";
      default:
        return "WSAEventSelect(): unknown error";
      }
    }
  }
  return NULL;
}

int do_eventsel_loop(HANDLE other_event)
{
  int n, nhandles, nallhandles, netindex, otherindex;
  unsigned long next, then;
  long ticks;
  HANDLE *handles;
  SOCKET *sklist;
  int skcount;
  unsigned long now = GETTICKCOUNT();

  if (toplevel_callback_pending()) {
    ticks = 0;
    next = now;
  } else if (run_timers(now, &next)) {
    then = now;
    now = GETTICKCOUNT();
    if (now - then > next - then)
      ticks = 0;
    else
      ticks = next - now;
  } else {
    ticks = INFINITE;
    /* no need to initialise next here because we can never get
     * WAIT_TIMEOUT */
  }

  handles = handle_get_events(&nhandles);
  handles = sresize(handles, nhandles + 2, HANDLE);
  nallhandles = nhandles;

  if (netevent != INVALID_HANDLE_VALUE)
    handles[netindex = nallhandles++] = netevent;
  else
    netindex = -1;
  if (other_event != INVALID_HANDLE_VALUE)
    handles[otherindex = nallhandles++] = other_event;
  else
    otherindex = -1;

  n = WaitForMultipleObjects(nallhandles, handles, FALSE, ticks);

  if ((unsigned)(n - WAIT_OBJECT_0) < (unsigned)nhandles) {
    handle_got_event(handles[n - WAIT_OBJECT_0]);
  } else if (netindex >= 0 && n == WAIT_OBJECT_0 + netindex) {
    WSANETWORKEVENTS things;
    SOCKET socket;
    extern SOCKET first_socket(int *), next_socket(int *);
    int i, socketstate;

    /*
     * We must not call select_result() for any socket
     * until we have finished enumerating within the
     * tree. This is because select_result() may close
     * the socket and modify the tree.
     */
    /* Count the active sockets. */
    i = 0;
    for (socket = first_socket(&socketstate); socket != INVALID_SOCKET;
         socket = next_socket(&socketstate))
      i++;

    /* Expand the buffer if necessary. */
    sklist = snewn(i, SOCKET);

    /* Retrieve the sockets into sklist. */
    skcount = 0;
    for (socket = first_socket(&socketstate); socket != INVALID_SOCKET;
         socket = next_socket(&socketstate)) {
      sklist[skcount++] = socket;
    }

    /* Now we're done enumerating; go through the list. */
    for (i = 0; i < skcount; i++) {
      WPARAM wp;
      socket = sklist[i];
      wp = (WPARAM)socket;
      if (!p_WSAEnumNetworkEvents(socket, NULL, &things)) {
        static const struct {
          int bit, mask;
        } eventtypes[] = {
            {FD_CONNECT_BIT, FD_CONNECT},
            {FD_READ_BIT, FD_READ},
            {FD_CLOSE_BIT, FD_CLOSE},
            {FD_OOB_BIT, FD_OOB},
            {FD_WRITE_BIT, FD_WRITE},
            {FD_ACCEPT_BIT, FD_ACCEPT},
        };
        int e;

        noise_ultralight(socket);
        noise_ultralight(things.lNetworkEvents);

        for (e = 0; e < lenof(eventtypes); e++)
          if (things.lNetworkEvents & eventtypes[e].mask) {
            LPARAM lp;
            int err = things.iErrorCode[eventtypes[e].bit];
            lp = WSAMAKESELECTREPLY(eventtypes[e].mask, err);
            select_result(wp, lp);
          }
      }
    }

    sfree(sklist);
  }

  sfree(handles);

  run_toplevel_callbacks();

  if (n == WAIT_TIMEOUT) {
    now = next;
  } else {
    now = GETTICKCOUNT();
  }

  if (otherindex >= 0 && n == WAIT_OBJECT_0 + otherindex)
    return 1;

  return 0;
}

/*
 * Wait for some network data and process it.
 *
 * We have two variants of this function. One uses select() so that
 * it's compatible with WinSock 1. The other uses WSAEventSelect
 * and MsgWaitForMultipleObjects, so that we can consistently use
 * WSAEventSelect throughout; this enables us to also implement
 * ssh_sftp_get_cmdline() using a parallel mechanism.
 */
int ssh_sftp_loop_iteration(void)
{
  if (p_WSAEventSelect == NULL) {
    fd_set readfds;
    int ret;
    unsigned long now = GETTICKCOUNT(), then;

    if (sftp_ssh_socket == INVALID_SOCKET)
      return -1; /* doom */

    if (socket_writable(sftp_ssh_socket))
      select_result((WPARAM)sftp_ssh_socket, (LPARAM)FD_WRITE);

    do {
      unsigned long next;
      long ticks;
      struct timeval tv, *ptv;

      if (run_timers(now, &next)) {
        then = now;
        now = GETTICKCOUNT();
        if (now - then > next - then)
          ticks = 0;
        else
          ticks = next - now;
        tv.tv_sec = ticks / 1000;
        tv.tv_usec = ticks % 1000 * 1000;
        ptv = &tv;
      } else {
        ptv = NULL;
      }

      FD_ZERO(&readfds);
      FD_SET(sftp_ssh_socket, &readfds);
      ret = p_select(1, &readfds, NULL, NULL, ptv);

      if (ret < 0)
        return -1; /* doom */
      else if (ret == 0)
        now = next;
      else
        now = GETTICKCOUNT();

    } while (ret == 0);

    select_result((WPARAM)sftp_ssh_socket, (LPARAM)FD_READ);

    return 0;
  } else {
    return do_eventsel_loop(INVALID_HANDLE_VALUE);
  }
}

/*
 * Read a command line from standard input.
 *
 * In the presence of WinSock 2, we can use WSAEventSelect to
 * mediate between the socket and stdin, meaning we can send
 * keepalives and respond to server events even while waiting at
 * the PSFTP command prompt. Without WS2, we fall back to a simple
 * fgets.
 */
struct command_read_ctx {
  HANDLE event;
  char *line;
};

static DWORD WINAPI command_read_thread(void *param)
{
  struct command_read_ctx *ctx = (struct command_read_ctx *)param;

  ctx->line = fgetline(stdin);

  SetEvent(ctx->event);

  return 0;
}

char *ssh_sftp_get_cmdline(const char *prompt, int no_fds_ok)
{
  int ret;
  struct command_read_ctx actx, *ctx = &actx;
  DWORD threadid;
  HANDLE hThread;

  fputs(prompt, stdout);
  fflush(stdout);

  if ((sftp_ssh_socket == INVALID_SOCKET && no_fds_ok) ||
      p_WSAEventSelect == NULL) {
    return fgetline(stdin); /* very simple */
  }

  /*
   * Create a second thread to read from stdin. Process network
   * and timing events until it terminates.
   */
  ctx->event = CreateEvent(NULL, FALSE, FALSE, NULL);
  ctx->line = NULL;

  hThread = CreateThread(NULL, 0, command_read_thread, ctx, 0, &threadid);
  if (!hThread) {
    CloseHandle(ctx->event);
    fprintf(stderr, "Unable to create command input thread\n");
    cleanup_exit(1);
  }

  do {
    ret = do_eventsel_loop(ctx->event);

    /* Error return can only occur if netevent==NULL, and it ain't. */
    assert(ret >= 0);
  } while (ret == 0);

  CloseHandle(hThread);
  CloseHandle(ctx->event);

  return ctx->line;
}

void platform_psftp_pre_conn_setup(void)
{
  if (restricted_acl) {
    logevent(NULL, "Running with restricted process ACL");
  }
}

/* ----------------------------------------------------------------------
 * Main program. Parse arguments etc.
 */
int main(int argc, char *argv[])
{
  int ret;

  dll_hijacking_protection();

  ret = psftp_main(argc, argv);

  return ret;
}
